WASHINGTON (AP) – Jack Lew is the model Washington insider – a savvy and cool policy technocrat with roots in Congress and a long and impressive administration resume. He is as low key as Rahm Emanuel, one of his predecessors as White House chief of staff, was high octane.

In choosing Lew to run his White House, President Barack Obama on Monday completed an arc of chiefs-of-staff, from the fiery Emanuel and his grasp of legislative intrigue, to William Daley and his ties to the business community to, now, Lew, a budget specialist with expertise on the inner workings of the executive branch.

Intensely private, Lew is often defined as a “pragmatic liberal,” one who embraces core progressive notions about the role of government but understands the need to find bipartisan solutions to control deficits and reduce the national debt.

Those who know him say Lew is slow to get frustrated, a particularly useful trait at a time of high partisanship.

At age 56, Lew’s career has placed him at the center of power for three decades. He was a top aide in the 1980s to then-House Speaker Tip O’Neill. His office mate in those days was Chris Matthews, now the colorful and occasionally combative MSNBC host.

Lew was director of the Office of Management and Budget, his current post, back in the Clinton administration, serving from 1998 to early 2001, prompting Obama to praise him as the “only budget director in history to preside over budget surpluses for three

consecutive years.”

“Over the past year he has helped strengthen our economy and streamline the government at a time when we need to do everything we can to keep our recovery going,” Obama said. “Jack’s economic advice has been invaluable and he has my complete trust, both because of his mastery of the numbers but because of the values behind those numbers.”

Lew is well-regarded by Republicans, though he is likely to be perceived as more of a partisan than Daley, who had a close relationship with the corporate community.

Former Republican Sen. Judd Gregg of New Hampshire, who worked with Lew on appropriations and budget matters, called Lew’s appointment a “solid choice.”

“He’s a very professional guy, he’s a straight shooter, he’s obviously partisan, but he knows his stuff,” Gregg said. “He always told you what he thought. He was very straightforward. He has a lot of credibility on the Hill.”

With his glasses and stiff, neatly parted dark hair, Lew is the picture of a green-eyeshades numbers cruncher. But his role goes far beyond spreadsheets.

He has had a hand in major policy decisions, from a Social Security deal reached between O’Neill and President Ronald Reagan in 1983 to President Clinton’s narrowly approved budget deal in 1997 to the recurrent budget encounters last year with congressional Republicans.

Lew has a home with his wife in a Bronx neighborhood and keeps an apartment in Washington. Both of his children are grown.

He attended Carleton College in Minnesota where his faculty adviser was Paul Wellstone, then a political scientist who would become a Democratic senator from the state. Lew graduated from Harvard in 1978 and received his law degree from Georgetown University in 1983.

After working with O’Neill and in the Clinton administration, Lew returned to New York during the eight years of the Bush administration to work as executive vice president of New York University and then as chief operating officer of a unit of Citigroup.

His appointment comes in a presidential re-election year, meaning Obama’s time and attention will be increasingly divided between the White House and his campaign operation in Chicago. If Daley represented a period when the Obama administration aimed to conduct more outreach with the business community, Lew’s appointment suggests a more inward looking period relying on the skills of a consummate insider deeply familiar with the machinery of government.